Conventional telecommunications infrastructure often utilizes a Time-Division-Multiplexed (“TDM”) approach to real-time communications, such as telephone conversations and videoconferences, in which a dedicated circuit is provided for carrying a plurality of communication streams. The TDM approach provides low latency (delay), which is desirable in delivering media such as voice. On the other hand, the TDM approach also requires the use of a dedicated connection, which in turn requires a relatively large amount of bandwidth. Also, the TDM approach to voice communications is frequently implemented via a public exchange and associated long-distance communications infrastructure, which can be expensive to develop and maintain.
Another approach to implementing communications flow is a packet-based approach. A packet-based approach tries to gain bandwidth efficiency by dividing data into discrete packets, and then sending the packets over a network via a “virtual” circuit utilizing, ideally, the most efficient available transmission path. Combining packets and supporting many more “connections” in such a manner provides an ability to support more communication flows within an amount of bandwidth comparable to the TDM approach.
The packet-based approach was originally designed for network traffic that did not require particularly low latency values. For example, an email may be easily sent over a network using the packet-based approach, since the packets can be reconstructed at a destination computer once all packets have traversed the network. Even if some percentage of packets are lost, the email or other such communication may often be reconstructed to a sufficient level of accuracy.
It would be advantageous to use the packet-based approach to transmitting low-latency communications such as voice, since the packet-based approach is efficient and does not require large levels of infrastructure. Delays and disruptions to low-latency communications such as voice in a packet-based transmission scheme, however, may easily damage the communications to the point that they become undesirable or unusable. For example, two people holding a phone conversation via such a system may find there is significant delay between an end of a spoken sentence by one user and the receipt of the sentence by the other user. Additionally, a level of static in the call may become so high that the users may be annoyed by the background noise, or may actually be unable to hear one another sufficiently well to continue the conversation. Similarly, parties on a videoconference may find the transmitted visual images to be undesirably or unsuitably low in quality.
What is needed is an approach that enables packet-based communications through a network, while reducing any associated variance in delay, or “jitter,” of the communications.